Bump protobuf from 3.19.4 to 5.29.2 in /sdks/python

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 3.19.4 to 5.29.2.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](protocolbuffers/protobuf@v3.19.4...v5.29.2)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

sdks/python/build-requirements.txt

@@ -25,7 +25,7 @@ grpcio-tools==1.37.0
 # pin grpcio to the previous version.
 grpcio==1.49.1;sys_platform=="darwin"
 mypy-protobuf==1.18
-protobuf==3.19.4;python_version=="3.10" and sys_platform=="darwin"
+protobuf==5.29.2;python_version=="3.10" and sys_platform=="darwin"
 
 # Avoid https://github.com/pypa/virtualenv/issues/2006
 distlib==0.3.1